Conventionally, as an electronic device that is mounted on the surface of a printed circuit board, there is, for example, a surface mount type leadless electromagnetic relay provided with: a coil assembly including an iron core, a coil spool containing the iron core with a part thereof exposed, and a coil wound around the coil spool; an armature assembly including an armature with one end thereof in contact with at least one end of the iron core, a movable contact spring having at least one movable contact at an tip thereof, and a support made up of an insulator that supports the armature and the movable contact spring; and at least one fixed contact that faces the movable contact, and a fixed contact terminal that holds the fixed contact. In the electromagnetic relay including a cover and an insulating substrate that houses the coil assembly inside, the movable contact, the movable contact spring, the fixed contact, and a terminal, which is electrically connected to an external electric circuit from the coil, is formed integrally with the insulating substrate, the terminal adhering to the bottom of the relay body and being extended thereon (See Patent Document 1).
As illustrated in FIG. 5C of Patent Document 1, the above surface mount type leadless electromagnetic relay is sealed by putting a cover 51 over an insulating substrate 3005 and filling a gap therebetween with a sealant 45. Then, the surface mount type leadless electromagnetic relay is electrically connected to the printed circuit board via solder.